The semiconductor integrated circuit (IC) has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased. Such advances have increased the complexity of processing and manufacturing ICs. For these advances, similar developments in IC processing and manufacturing are needed.
MEMS (microelectromechanical system) devices, such as accelerometers, pressure sensors, gyroscopes, etc, have found widespread use in many modern day electronic devices. For example, MEMS accelerometers are commonly found in automobiles (e.g., in airbag deployment systems), tablet computers, and in smart phones.
In recent years, it is increasingly common for MEMS devices to be incorporated into integrated chips formed by a complementary metal-oxide semiconductor (CMOS) process. The incorporation of MEMS (e.g., sensors, integrated optics, biochips, etc.) into a CMOS process allows for widespread use of MEMS.